Metalworking machine



Filed Nov. 9, 1940 13 Sheefcs$heet l Feb. 9, 1943. M. H. ARMS METALWORKING MACHINE l5 Sheets-Sheet 2 Filed Nov. 9, 1940 ru w:

Feb. 9, 1943. M. H. ARMS METALWORKING MACHINE l3 Sheets-Sheet 5 Filed Nov. 9;, 1940 [Wm/07 $73 l 117%! Feb. 9, 1943. M. H. ARMS METALWORKING MACHINE Filed Nov. 9, 1940 13 Sheets-Sheet 4 HEM-EVE mil m IIILI.

Feb. 9, 1943. M. H. ARMS METALWORKING MACHINE Filed Nov. 9, 1940 13 Sheets-Sheet 5 R x d.E.1:12.25: $3 v Emil/w qlll Feb. 9, 1943. M. H. ARMS METALWORKING MACHINE l5 Sheets-Sheet 6 Filed NOV. 9, 1940 Feb. 9, 1943. M. H. ARMS METALWORKING MACHINE Filed Nov. 9, 1940 15 SheetsSheet '7 f &

Feb. 9, 1943. M. H. ARMS METALWORKING MACHINE Filed Nov. 9, 1940 15 Sheets-Sheet 8 Feb. 9, 1943. M. H. ARMS METALWORKING MACHINE.

Filed Nov. 9, 1940 15 Sheets-Sheet 9 Feb. 9, 1943. ARMS 2,310,338

METALWORKING- MACHINE Filed NOV. 9, 1940 13 Sheets-Sheet 10 $1 Q g N IIA III Feb. 9, 1943. M. H. ARMS METALWORKING MACHINE Filed Nov. 9, 1940 is Sheets-Sheet 11 172W? /WW6 Feb. 9, 1943. M. H. ARMS METALWORKING MACHINE Filed Nov 9, 1940 13 Sheets-Sheet l2 Feb. 9, 1943. M. H. ARMS METALWORKING MACHINE Filed Nov. 9, 1940 13 Sheets-Sheet 13 i M S i KL 3 Q m %%.w

w R Q Q A i vii y 2 E wgi 5 S Q E g a 3 2 W MW m M Patented Feb. 9, 1943 Bryant chucking Grinder Company, Springfield, Vt., a corporation of Vermont Application November 9, 1940, Serial No. 365,071 g 17 (liaims.

This invention relates to metal working machines and while not. restricted thereto, the machine herein shown has been designed more particularly for internal grinding.

One of the objects of this invention is to avoid the use of overhead structure thus facilitating the placing and removal of work and access-to.

Still another object is to provide improved traverse" limit stop mechanism.

Another object is to provide hydraulic controlling and actuating mechanism.

A further object is to provide rigid support for the wheel when the stroke is relatively long.

Still another object is to provide for recep tion of work heads of a great variety of types.

For a more complete understanding of this invention, reference may be had to the accompanying drawings inwhich 7 v a Figure 1 is a front elevation of a grinding machine embodying the invention.

Figure 2 is a top plan of the same.

Figure 3 is a right end elevation of the machine.

Figure 4 is a detail section on line 4-4 of Fig ure 3.

Figure 5 is a fragmentary longitudinal section on line 75--5 of Figure 2. a

Figures 6 and '7 are detail sections on lines 6- 8 and 1-1, respectively, of Figure 5.-

Figure 8 is a view similar to a portion of Figure 2, but to a larger scale and showing parts in dotted lines.

Figures 9 and 10 are detail sections on lines 9-9 and ill-10, respectively, of Figure 8.

' Figure 11 is a detail section on line ll-ll of Figure 10. I

Figure 12 is a view similar to Figure 6, but showing a modification.

Figure 12a. is a view similar to a portion of Figure 4, but showing a further modification.

Figure 12b is'a ,view similar to a portion of Figure 6. but showing the same construction as Figure 12a.

Figure 13 is a view similar to Figure 9, but showing a modification. Figure 14 is a view similar to a portion of Fi ure 13, but showing the parts in different positions.

Figures l5 and 16 are detail sections on lines I5I5 of Figure-l3 and l6'-l6- of Figure 14, respectively.

Figure 17 is a view similar to a portion'ot Figure 1, but showing the modification of Figures 12 to 16, inclusive.

Figures 18 and 19 are'detail sections on lines l8-l8- and lB-IS, respectively, of Figures 2 and 8.

Figure 20 is a fragmentary view-partly in elevation and partly broken away and in section of the wheel feed mechanism.

Figure 21 is a view partly'in side elevation and partly in vertical section of a traverse limit stop. Figure 221s ajview similar to a portion of Figure 21, but with parts in different positions and with a different action.

Figure 23 is a detail section on line 23-43 of Figure 22.

Figure 24'is a view similar to a portion of Fi ures 21 and 22 but showing a modification.

Figure 25 is a detail section on line 25-25 of Figure 24. g

Figure 26 is a top plan view of a portion of the hydraulic control box. 25

Figures 27, 28 and 29 are detail sections on the correspondingly numbered section lines of Figure 26.

Figure 30 is a detail section on line 3il30 of Figure 27.

Figure 31 is a diagram of, the wheel slide hy- Figure 32 is a view similar to a portion of Figure 31, .but with the parts in position for reverse direction traverse. a

Figures 33,- 34 and 35 are views similar to a por-' tion of Figure 31, but showing the automatic reversing valve in dress, stop and fast positions, respectively. Figures 36 is a diagram of the hydraulic control of the workdriving motor.

Woax CARRIAGE Mounrms AND Connor.

Referring first to Figures 1 and-2,-the machine as shown comprises a base i having a bed 2 at one end portion provided with a pair of transverse ways 3 and 4 (see Figures 5 and 10) on its upper face.

bearings 6, I and 8 (see Figures 5 and 8).

The bearings 6 which ride on the way 3 comprise cartridges .having'ways l0 (seeFigures 8, 10 and 11) for supporting a series of balls II in continuous array, the balls on the lowerstretch engaging the upper face of the way 3 and the ballson the upper stretch on the return being held in place by a cover plate 1-2. Each of these cartridges, two being shown, are pivotally supported on a pivot pin I5 between a pair of On these ways is mounted a work supporting carriage 5. The means for mounting this carriage 5 comprise antifrictionwalls l6 and H depending from the lower face of the carriage 5. These bearings 6 are arranged to take vertical thrust only.

The bearings l are arranged with ball ways for supporting a series of balls in horizontal array and engage a vertical wall IS on the way 4 and also a horizontal wall I9, these hearings being thus arranged to take both vertical and horizontal load. These bearings are mounted on vertical pivots 20.

To take the side thrust from the bearings 1 are cylindrical bearing members 2| (see Figure 8) carried by levers 22 fulcrumed at 23, the opposite end of these levers being engaged by the ends of bars 24 pressed thereagainst by the springs 25 in the carriage 5.

As shown in Figure 11, the pivots |5 for the bearings 6 have eccentric middle portions 3|] oarrying the cartridge. The outer end of each pin is mounted in a plate 3| adjustably secured to the outer face of the wall member |6 as by the arcuate slot and bolt construction shown at 32. Angular adjustment of the plate rocks the portion and thus raises or lowers the carriage 5 about the row of balls engaging the wall I8 as a center. Angular adjustment of the carriage 5 about this row of balls may be employed to bring the substantially horizontal planes of the work and wheel axes into exact parallelism to permit, with proper angular adjustment of the work holder, a facing wheel such as |53 to contact the'end face of the work both above and below its rotational axis. This anti-friction mounting of the slide per se is not claimed herein but forms subject matter of a co-pending application, Serial No. 220,294, filed July 20, 1938, for Antifriction slides, now Patent No. 2,230,442 granted February 4, 1941. The top face of the carriage 5 is provided with a pair of arcuate under-cut guide tracks and 36 to which may be adjustably secured a support 40 within which is journaled a work-carrying spindle 5| which carries a suitable work-supporting chuck 62 at its inner end and is shown with belt pulleys 63 at its outer end. By this mounting the axis of the Work spindle may be adjusted angularly throughout a wide range with respect to the lengthwise axis of the machine and with respect to a traversing tool carriage which will later be described. Bolts (see Figure 2) engaging in the under cut guide members 35 and 36 may be employed to secure the spindle in the desired angularly adjusted position. For driving the spindle 4| there is shown a reversible hydraulic motor 5|] carried by the support 40 and having belt pulleys 5| which may be connected with the belt pulleys 43 by suitable belts 52.

The top face of the carriage 5 may be provided with a coolant-receiving depression 53 which leads the coolant backwardly through a trough 54 where it may pass from the back of the machine as through a pipe 55.

The work carriage may be moved transversely of the machine as for positioning and feed. For this purpose the top portion of the machine bed, as shown best in Figure 9, may have secured thereto a bearing 6|] within which a nut member 6| is rotatably mounted, but held against axial motion. The nut member 6| has threaded engagement -with a lead screw 62. This nut member 6| is shown as provided with a worm wheel portion 63 with which meshes a worm 64 on a shaft 65. When the shaft 65 is stationary, the nut member 6| is held against rotation, but rotation of the screw 62 may then be employed to move the work-holding carriage. To this end the lead screw 62 extends through a bearing sleeve 66 secured in a bracket member 61 attached by means such as screws 68 to the forward face of the work carriage 5 and to the forward end of this lead screw 62 is keyed a hand feed wheel 10 by which it may be rotated.

Means may be provided for locking the lead screw 62 against rotation and also for producing when desired a slow feed rotation thereto. To this end, the lead screw 62 has secured thereto between the bearing bushing 66 and the wheel 10 a worm wheel I I, and as shown best in Figure 18 this worm wheel may be engaged by a worm 12. The worm I2 is carried by a shaft 13 which is journaled longitudinally of a lever I4. This lever is fulcrumed at 15 and by upward rocking of this lever, the worm 12 may be lifted out of contact with the worm wheel H as shown in the dotted line position of Figure 18. When so lifted the hand wheel 10 is free to be turned. thus rotating the lead screw 62 for relatively fast motion.

When the lever 14 is in the full line position shown in Figure 18 with the worm 12 in engagement with the worm wheel 1|, the lead screw 62 is locked against rotation by means of the wheel 10, but it may be given a slow rotation by rotation of the shaft 13 carrying the worm 12. For this purpose the outer end of the shaft 72 has secured thereto as by a set screw 16 a small hand wheel 11. The lever 14 is mounted in a portion of the bracket 61 and is normally substantially covered by a cover plate 18.

As before noted, motion of the work carriage 5 may be produced by rotation of the nut member 6| by rotation of the shaft 64. As shown best in Figure 19, this shaft 64 is journaled within a sleeve and has keyed to its outer end a hand wheel 8| provided with actuating handles 82. Inwardly of the hand wheel 8| there is rockably mounted on a bushing 84 within which the shaft 66 is journaled the hub 85 of a bell crank lever having an arm 85 and an arm 81. (See Figures 19 and 20.) The arm 81 has pivoted thereto a feed dog 88 adapted to engage the teeth of a ratchet wheel or ring 89 secured to the inner face of the hand wheel 8|, so that by rocking of the bell crank lever a relatively slow intermittent turning of the hand wheel 8| may be produced thus to effect a slow power feed of the work carriage through the slow intermittent rotation of the shaft 64. This feed through rotation of the shaft 64, is, of course, unaffected by the locking of the screw 62 against rotation.

A ring member 90 having a suitable pawl knock-off may be rotatably supported between the ratchet 89 and the back face of the hand wheel 8| and it may be provided with internal teeth meshing with a pinion 92 of a shaft 93 projecting through the hand wheel 8| and carrying a knob 94 on its outer end by which it may be turned, thereby to adjust the angular position of the knock off ring 90 and thus to determine the extent of feed by rocking of the bell crank lever arm 86. For the purpose of rocking this bell crank, its arm 86 is operatively connected to the upper end of a feed actuating hydraulic plunger 95 working in a cylinder 96 and normally held elevated as by a spring 91. The operation of this feed mechanism will be more fully described in connection with the hydraulic system.

In some cases it may be found desirable to provide for a quick retraction of the work slide in dependently of and without effecting the feed adjustment between the lead screw and the lead nut as previously described. Such a construction is illustrated in Figures 13 to 16, inclusive, wherein instead of forming the lead screw as a solid screw, it is formed as a sleeve 62a within which is slidably and non-rotatably mounted a splined shaft I00. This splined-shaft I is journaled against axial motion in the bracket 61, and is provided with a collar I 0| forming a shoulder against which a shoulder I02 on the outer end of the lead sleeve 62a may impinge. When these parts are in contact, as shown in Figure 13, the feed of the carriage -5 is controlled either by the rotation of the lead screw or the lead nut in the same manner as in the constructions illustrated in Figures 8, 9, 18, 19, and 20, but when de sired the carriage may be moved forwardly as is shown in Figure 14, causing the collar IN to be moved away from the shoulder I02. This may be done, for example, by fluid pressure means as illustrated in Figure 13. A fluid pressure cylinder I05 having a piston I06 therein is secured to the bed of the machine as by the screws I01, and the piston rod I08 carries at its forward end a spool shaped member I09 mounted for sliding motion in a-trough shaped guide member IIO. Depending from the carriage 5 is a headed pin III having a forked end portion II2 which engages between the heads I I 3 and I I4 of the member I09 and preferably extends down on each side of its central reduced diameter portion as shown best in Figure 15. By allowing fluid under pressure to enter back of the piston I06 as through the pipe H5, and allowing fluid to escape through the pipe H6, the carriage 5 may be pushed forwardly into the position shown in Figure 14 with a quick motion. By introducing fluid under pressure to the pipe II6 on the forward face of the piston I06 and discharging through the pipe N5, the piston I06 may be returned to the position of Figure 13, whereupon the normal motion of the carriage 5 through rotation of its lead screw or nut may be resumed. This quick motion under fluid pressure may be done without in any way disturbing the settings of the screw and nut mechanism.

T001. CARRIAGE MOUNTING AND CONTROL The tool herein shown as a grinding wheel I50 is carried :by a rotatable shaft I5I journaled in a long quill I52 carried by a wheel head bracket I520 and there may be, if desired, a second tool or grindingwheel I53 carried by a shaft (not shown) journaled in a quill I54 in a second wheel head bracket I55. These brackets are shown as carried by a base-I56 which has dovetail connection with a supporting hollow block I51 and support the grinding wheel shafts outwardly of the bore I56 allowing a long grinding stroke with rigid support of the grinding wheels. This block I51 is carried by a carriage I58. This carriage is rockably supported by a tube. or hollow bar I59 which is slidably and rockably mounted on semi-cylindrical bearing members I8I. Extending into the tube I59 is a shaft I 60 provided with an enlarged diameter portion I6I which slidably fits within the tube I59 and forms a piston therefor.

The shaft I60 has reduced diameter end portions I62 and I63. The portion I62 is hollow and through the center thereof .passes a .pipe I64 which extends into the piston portion I6I and communicates through a port I65 to the interior of the tube I59 to the right of' the piston as shown in Figure 5.' The space outwardly of the pipe I64 and between it and the inside of the shaft portion I62 communicates through the port I 66 with the left hand side of the piston I6I. The shaft portion I 63 is solid in cross section and is slidably guided through a sleeve I61 which engages a larger internal diameter portion of the tube I59 and formsa closed end to the pressure cylinder which travels relative to the piston I6I.

The right hand end of the tube I59 is open but the left hand end is closed by a bushing I10 havmg a portion filling the space between the outside of the shaft portion I62 and the inside of the tube I59. A second collar I1I secured against the left hand end of the tube I59 and areduc ed diameter portion of'th collar I10 completes the closure of this end of the tube I59 to the hollow piston rod portion I62. The inner end of the bushing I10 and the adjacent face of the piston I6I have mating concentric stepped portions which act as a dash pot to cushion the slide motion at the outer limit of its motion.

This tube I59 thus forms a fluid pressure cylinder, fluid under pressure being introduced into the pipe I 64 and discharging through the port I66 and pipe I 15 serving to force the tube I59 and the tool carriage carried thereby to theright from the position in Figure 5, while fluid introduced into the space between the pipe I64 and hand and of the shaft portion I62 extends through a bushing I16 loosely mounted in an end wall member I 11 secured as by screws to the machine base I and on the left hand end of this portion I62 there is positioned a nut I18 which holds the shaft I62 in position. The loose mounting of the bushing I16 prevents cramping of the shaft portion I62, and a yieldable sealing ring I18a prevents the escape of oil around this bushing. The pipe I15 then enters into an open ing in an end cap I19 into which also extends the pipe I64 with which communicates a second pipe I80. The right hand end of the tube I59 may be covered by a hood I82 which is telescopically related to a second hood member I89 into which the right hand end of the tube I59 may pass when the tool carrier is retracted to its greatest extent. A guard or shield I84 is secured to the left hand end of the carriage I58 and having downwardly and. outwardly sloping top faces overlying the tube I59 extends beneath the bed I and has transversely extending top ribs for directing foreign matter laterally.

The carriage I58 and the member I82 are provided wih a pair of spaced inclined ways I85 and I86, respectively, on which may be adjustably supported a pair of slides I81 and I88 which support between them belt tightener pulleys I89 and I90. Thesepulleys engage belts I! and I92, respectively, which pass over a driving pulley I93 of a-driving motor I94 and over pulleys I95 and I96 on the grinding wheel shafts I 5| and one (not shown) journaled within the quill I54, respectively. The motor I94 is carried by the tool carriage as shown in Figure 6, being bolted to the lower face thereof, so that it partakes of the mo tion of this carriage and remains in the same relation to the grinding wheel pulleys I and I96 at all times.

It will be noted that the tool carriage extends thereof so that its rear end may be supported by gravity on a support by which it may be guided in its reciprocating motions. Referring to Figures 4 and 6, the support for the rear end of the tool carriage comprises a block 200 rockably supported on a pin 20| between spaced portions 202 and 203 of a bracket 204 secured to the machine frame. Resting upon this block 200 is a former cam 205 which is-carried by the tool carriage with capability of adjustment relative thereto. As shown it is supported on a screw 206 which passes through a pivot bushing 20'! extending through a foot member 208 which may be integral with the tool carriage. The inner end of the screw 208 carries a washer 209 pressed against the forward end of the bracket 200 as by a spring 2|0 surrounding this pin and reacting between the washer 209 and a nut 2ll threaded on the forward end of the pivot pin. Opposite end portions of the former cam 205 may be adjusted up and down and for this purpose the top of the former cam is shown as backwardly and downwardly tapered as at 2|2 for cooperation with the reversely tapered face 2|3 of an adjusting block 2| 4. Each adjusting block is mounted for sliding motion between spaced splined faces 2l5 and 2I6 of the portion 208 and may be adjusted forwardly and backwardly as desired by the rotation of an adjusting rod 211 which at its rearward end is threaded into the corresponding block 2i4. A spring 2!!! surrounding the rear end portion of the bar 2H and reacting between the forward face of the block 2 I4 and a rear face 2lil of the member 200, forces the block 2l4 rearwardly as far as is permitted by the engagement of a collar 220 engaging a portion at 22l of larger diameter than the threaded end portion of the bar 2H on the forward face of the member 203. The two bars i2! extend through the tool carriage and terminate at their forward ends in socketed extremities 223 with which a suitable tool may be engaged by which the corresponding bar 2|! may be turned, thus to adjust the corresponding end of the former cam 205 about its pivotal axis. The contour of the lower face of this former cam and the angular adjustment thereof determine the positions of the grinding wheels with relation to the rocking axis of the carriage for the various traverse positions of the tool carriage. If this former cam is flat on its lower face and is arranged parallel to the axis of the wheel and the work axis is in the same plane with the slide bar axis, a cylindrical hole will be formed in the work, but if the former cam is tilted, a tapered hole is formed, and if the former cam has a guiding surface other than fiat, a surface having a corresponding contour will be ground in the work, with or without an additional taper component, depending on the angular setting of the former cam.

Where two wheels are employed as shown, the wheel I50 may be employed for internal grinding and the large wheel I53 may be employed for face grinding the end of the work carried in the chuck 42. The former cam would, of course, be used to control the position of the grinding wheel I50 in the various portions of its grinding path. The grinding wheel I53 when used for face grinding would receive no benefit from this former cam since this grinding wheel then performs no grinding action on an axial surface of the work.

While the feed of the work may be produced by movement of the work holder itself and the former cam be employed to control the shape of the course. possible to produce a relative feed between the wheel and the work by tilting the tool carriage, in addition to the control by the former cam in accordance with the axial position of the wheel at any given time. In Figures 12 and 17 is illustrated a modified construction wherein this additional feed independent of the former cam contour and angular position may be afforded. The abutment on which the former cam rests as shown in Figure 12 is a block or roller 230 which may be held as on a pivot 23l between a pair of spaced jaws 232 at the upper end of a plunger 233 mounted for up and down motion within a bushing 234 to which it is shown keyed as by the key 235. This bushing 234 is mounted in a bracket 236 suitably secured to the back of the machine base. The lower end of the plunger 233 as'at 231 is shown as threaded through a sleeve 238 journaled in a bushing 239 carried by the bracket 236. The lower end of this sleeve 238 has a bevel gear 240 secured thereto with which meshes a bevel pinion 24! on a shaft 242. This shaft242 extends to the forward face of the machine where it has fixed thereto a gear 243. This gear 243 meshes with a gear 244 joumaled on a stub shaft 245 and this gear 244 in turn meshes with a driving pinion 246 on a feed sleeve 24! journaled on a stub shaft 248. A hand operated feed wheel 249 is shown as keyed to the sleeve 241, by the turning of which through the gear train described, the plunger 233 is adjusted vertically, thus to produce a tilting feed motion of the wheel carriage.

In Figures 12a and 12b a further modification is shown in which the former cam 2050 is carried by the machine frame and supports a follower roll 205i carried by the tool carriage. This roll 205i is journaled on an eccentric central portion 2052 of a shaft 2053 journaled in spaced walls of the tool carriage, and this shaft 2053 may be angularly adjusted by rocking an arm 2054 secured to its outer end and secured by a screw and slot connection at 2055 to the carriage in adjusted angular position. The former surface ground as heretofore described, it is, of

cam 2050 is pivoted on a pin 2056 in a recess 2057 in the machine frame and is retained in position in the recess by a cover plate 2058 secured in position as by screws 2059. Opposite ends of the former cam 2050 are supported on the adjusting studs 2060 having locking nuts 206i thereon seated in recesses 2062 in the outer face of the machine frame. Angular adjustment of the arm 2054 provides a fine angular adjustment of the tool carriage about the axis of the tube i59 as does angular adjustment of the pin 20! in the construction of Figure 6, while angular adjustment of the former cam 2050 may be employed to determine the angular positions of the carriage in relation to its axial positions, as in the construction of Figure 6.

Posrrrvs Sror Maommsm carriage this bracket 260 is provided with a bore for the slidable reception of a stop bar 26L This bar, as shown, is provided with spaced rack teeth increments determined by the spacing of the rack teeth 262. This latching may be accomplished by a latch pin 264 vertically slidable in a bore 265. The lower end of the latch pin 264 is provided with a tooth 266 shaped to engage between adjacent teeth 262 of the rack bar. The

tooth 266 is held in proper angular position to.

cooperate with the rack bar 26I as by means of a key plug 261 engaging in a slot 266 cut longitudinally in the latch pin and provided at its outer end with a head 269 by which it may be removed when desired. The latch pin is provided with a head 210 riding in an enlarged diameter portion 21I of the bore 266 and on this head engages the lower end of a coil spring 212 which reacts against a, closure plug 213 threaded into the upper end of the bore portion 211. By rocking the bar 26I as through a handle 218, latched in position therein by a spring pressed ball 216, the latch pin 265 may be forced upwardly out of engagement between the rack teeth, whereupon the bar 265 may be shifted axially to the desired extent and the bar then returned to its former angular position, allowing the latch to lock it in axial position. The latch may, however, be held in retracted position as by the engagement of an axially moving locking pin 216' in a socket 211 in the latch pin. This locking pin may be secured in sliding position by a set screw 218 having its When be placed in the groove 263 between its end inner end engaged in a, slot 219 in the locking pin, and a head 211 thereon facilitates its manipulation.

The stop bar 26I .forms one of the stop elements, which when contacting with the other,

limits the inward motion of the tool carriage with respect to the work carriage. As, however, this stop element is adjusted by definite increments, its cooperating stop element should be adjustable for all positions intermediate these definite increments. The cooperating stop element shown, therefore comprises a stop bar 280 having a stop member 28I adjustably threaded on the extension 282 threaded into the member 280. A plunger 283 slidable within a bore 284 in the externally threaded portion of the extension 262 and spring pressed by the spring 285 against the base of the externally threaded portion of the member 28! produces friction tending to prevent accidental turning of the stop member 28I.

The rear end of the bar 280 is shown as threaded into a sleeve 290 within ahousing 2'9I secured to theother portion of the machine such as the frame. Thus sleeve 290 is shown as provided with peripheral worm teeth at 292 for engagement with a worm 293 on an adjusting shaft 294. This shaft 294, as shown in Figure 20, may extend out to the forward face of the machine and have secured thereto a hand wheel 295 by which it may be turned.

In place of adjusting the bar 26I by definite increments, this construction provides for the use of gaging blocks of predetermined sizes which may be changed as desired. Where this type of adjustment is desired, the bar 26I'isturned to present its groove 263 upwardly, the latch 265 being-held in retracted position as shown in Figshoulder 263a. and a hardened socket plug 30I inserted in an opening 302 of the bracket 260, these parts then determining the stopping position of the outer end of the stop bar 26I. sides of the bar 26I adjacent to the shoulder 293:; may be cut away to facilitate the placement and removal of the gage block 300.

A further arrangement of stop elements may be employed as shown in Figures 24 and 25. As shown in Figure 24, the stop bar 26I is replaced by a bar 305 having a flange 306 separated by a narrow slot 3060 from an abutment block 301 and this block 301 and also the flange 306 may have mating perforations for the reception of the threaded ends 309 of a series of adjustable stop plugs 3I0 arranged in circular series about the axis of the bar 305. Tightening of screws 306 seated in the part 301 and threaded into the flange 306 narrows the slot 3060 and restrains the plugs 3") against turning by vibration or other accidental cause. The bracket 260 may be provided with a series of perforations 3I5 arranged in circular series and of suchsize as to permit the ends of the stop plugs 3! to enter therein in case they are of sulflcient length to do this. The bar 305 is so angulariy adjusted that any selected one of these stop plugs 3I0 is in position to engage the socket plug 3M and the stop plug 3"! in this position determines the stop limit of the bar 305 at that time, while any of the stop plugs 3") which are longer than the one in controlling position may project backwardly into the corresponding perforation 3I5 and be ineffective. Any stop plugs 3! which happen to be shorter than the one in the controlling position, of course, do not reach the face of the bracket 260 when the bar 305 is in its limiting position.

HYDRAULIC DRIVING MECHANISM AND CONTROL Tool carriage traverse The hydraulic mechanism for eflecting travdischarged through the pipes I15 and I shownin detail in Figure 5 as previously described. The movable cylinder I59 is indicated diagrammatically in Figure 31, this cylinder supporting the tool carriaga' Liquid is pumped from the tank 350 by the pump 35I into the pipe 352. A limiting pressure valve 353 communicating with the pipe 352 and discharging to the tank 350 through the pipe 354 acts to maintain pressure in the pipe 352 at the desired amount. This pipe 352 leads to a valve casing 3540 within which is positioned a pilot valve 355 and a reversing valve 356. It also leads through the pipe 351 to a valve casing 358 containing'an operator actuable controlling valve 359' and a shut off valve 360, which may be actuated at suitable times to cut out the automatic valvewithin the casing 3540 when hand control of the traverse is desired. In

the position shown in Figure 31 for automatic grinding traverse, liquid under pressure passesfrom the pipe 352' through the passages 365 and 368, the valve port 369, to the pilot valve, through the longitudinal passage 31I in this valve, through the port 312, the passage 313 and the passage 314, through the check valve 3130 and throttle valve 313i and later through the pipe 439 only, when the valve closes the port 4310 to the left end of the reversing valve 366, thus forcing the reversing valve 356 into the position shown, the fluid under pressure escaping from the right hand end ofthis valve first through the pipes 436 and 439, and later through the pipe 439 only, when the valve closes the port 4310 the throttle valve 4390, passage 438, port 431, through the valve passage 435, port 31, passage 443 and pipe 444 to the discharge pipe 4I9. A check valve 439I in the pipe 439 prevents free discharge through the pipe 439 so that the rate of flow and thus the rate of motion of the reversing valve near the end of its stroke is determined by the setting of the throttle valve 4390. This adjustment of the speed of motion of the reversing valve allows for a sharp control of the cut ofi for the tool slide so that the slide is stopped at a definite point. In this position of the reversing valve, fluid under pressure around the neck 366 of the reversing valve may pass through the passage 315 around the neck 316 of the valve 360, port 311, around the neck 318 of the hand operated valve 359 and out through the port 319 to the pipe I15, thus forcing the cylinder I59 to the left. The discharge from the opposite end of the cylinder takes place through the pipe I 80, the port 380, around the neck 38I of the manual control valve 359,-through the port 382, around the neck 383 of the valve 360, through the pipe 385, through the port 380, around the neck 381 of the reversing valve, through the port 388 and passage 389, the port 390 of the pilot valve, around the neck 39I of this valve, the port 392, and the pipe 393 to a valve casing 394. Within this valve casing 394 is a rocker valve 395 having two ports 396 and 391 therearound. The port 396 is a restricted port, the extent of opening of which may be adjusted by turning the valve 395, thus to determine the rate of discharge of fluid from the cylinder I59 and thus to determine the traverse rate. The port 391 is always wide open until after port 396 is wholly closed, but in grinding position no liquid passes therethrough as will later appear. The parts in this figure are in the grinding condition during which the-port 396 allows the discharge through the pipe 398 into the port 399 of the manual control valve 400 which is verticallly movable to any selected of four positions in any of which it may be yieldably retained as by a ball detent 40I shown in Figure 2'7, and determines in order whether the control is set for grinding, dressing, stop or fast speed.

In Figure 29 these four positions, grinding, dressing, stop and fast speed are shown indicated by the corresponding angular positions in a vertical plane of a control handle 408 which carries a mutilated gear 402 meshing with a pinion 403, which, in turn, meshes with a rack portion 404 and the valve 400. This valve is also permitted a rocking motion, this for the purpose of controlling the axial position of the pilot valve 355, one end of which is formed as a rack bar 405 with which meshes a gear 406 on the lower end of the valve 400. The rocking motion of this valve 400 does not, however, affect in any way its control of its valve ports and the handle 408 rocks with it in a horizontal plane.

In the grinding position shown for this valve 400 in Figure 31, the discharge from the pipe 398 and the port 399 passes around the valve 400 to the pipe 4I3, around the valve neck M0 and through the port M2 and pipe 4I4, both pipes 4| 3 and M4 leading to a valve casing 4I5 within which is a rockable valve M6. The pipe M3 is always open to the pipe 398 through an annular passage around the outsideof the valve 400 reregardless of the position of the valve 400. The valve MS has a pair of ports M1 and M8, both of which, in the position shown in Figure 31, communicate with the discharge pipe 4I9 leading back to the tank 350. Beside passing through the pipe 398 to the valve 400 there is also a by-pass discharge from the pipe 399 through an adjustable restricted rocker valve 420 having the V port 42I, through the pipe 422, the port 423 of the valve 400, which also leads around the neck MB of this valve from which the discharge takes place, as previously described. The port 391 of the adjustable valve 395 leads through a pipe 426 to a port 421 of the valve 400, but in this position of the parts, this port 421 is closed by the part 428 of the valve 400 so that in grind position the traverse speed is controlled by the extent of opening of the port 396 of the valve 395. The pilot valve is also forced fully to its right hand position by a load and fire" hydraulic means, since as soon as this valve has been moved far enough to open the valve passage 31I to pressure, this pressure acts on the left hand face of the valve shoulder 3550 while the shoulder 355I at the right hand end of the pilot valve is open to discharge through the valve passage 435.

When the tool carriage approaches the left hand end of its travel, a dog 430 thereon engages the head 43I of the valve 400 and continued motion of the carriage rocks the valve 400 and moves the pilot valve 355 axially toward the position shown in Figure 32 to which it is forced by the hydraulic load and fire, fluid under pressure passing to the right hand face of the shoul der 355I through the valve passage 435 and being discharged from the left hand face of the shoulder 3550 through the valve passage 31I, as will appear. In this position of the valve 355, the valve passage 31I has been moved out of registry with the port 369 and a valve passage 435 placed in registry therewith, thus permitting the fluid under pressure to pass through this passage 435 through the valve passage 436 and the port 431, the passage .438, and the passage 439 to the right hand end of the reversing valve 356, thus driving the reversing valve to the left to the position shown in Figure 32, while the left hand end of the reversing valve discharges through the pipe 314, the passage 3132 the valve port 440 around the neck 44I of the pilot valve through the valve passage 31!, the port 442, passage 443, and pipe 444 to the discharge line 4I9, With the reversing valve in this position, fluid under pressure passes from the pipe 352 and port 365 around the neck 381 of the reversing valve, port 386 to the pipe 385 leading to the manual traversing valve casing, around the neck 383 of the valve 360, passage 382, around the neck 38| of the hand control valve, and through the pipe I to the power cylinder I59 to drive the carriage in the reverse direction or to the right, the discharge taking place through the pipe I15, past the neck 318 of the hand control valve, neck 316 of the valve 360, the passage 315, around the neck 366 of the reversing valve, through the port 445, passage 446, port 441, around the neck 39I,

' through pipe 393, past the valve 395 and from thence back around the valve 400 and through the valve 4| 6 to discharge. This takes place until the dog 448 impinges on the valve 400'and 2,sro,sss I '7 rocks it back toward its initial position to which it is forced by the hydraulic load and tire mechanism previously described, whereupon the cycle is repeated. It will be noted that neck 39I oi the pilot valve is provided with conical ends which eiiect initial and final throttling through the ports controlled thereby, thus slowing the traverse before reversing and returning.

In the dress position the valve 499 is lowered to the position shown in Figure 33 in which it is too low to be ailected by the dog 448 so that the tool carriage is permitted an extended outward traverse at which time the dog 449 becomes eflective to reverse the traverse at one end while the dog 439 is still in effective relation at the other end. From an inspection 01 Figure 33 it will be seen that in this position of the valve 499 it shuts ofi port 399 from around the neck 419 and the discharge through the .pipe 4, but does not prevent flow from this port around the valve to the pipe 4I3. This permits the tool slideto retract and remove the wheel from the work at normal traverse speed until the wheel approaches dress position, whereupon the dog 495 engages the rabbit ears 466 and shuts d the valve port 4I1 while leaving open the port 8. All the discharge is then forced to take place through the throttle valve 42L pipe 422, around the valve neck M9 and through pipe did, so that the outward travel of the'wheel carriage, is slowed for dressing. The wheel, therefore, comes out of the hole in the work and returns at grinding speed, but its traverse is slowed during the truing portion of its extended traverse. 'Automatic reversal of this extended stroke is produced by the dog 449, turning the valve 499.

On depressing the handle 498 to the stop position indicated in Figure 29, the valve 499 is brought into the position shown in Figure 34.

In this position of the valve, it will be noted that there is open communication through ports 455 and 455 between the pipes 451 and 459. These pipes communicate with the pipes 385 and 315, respectively, which in the inoperative position of the hand traverse valve 359, communicate with the pipes I15 and 189 which lead to opposite ends of the power cylinder I59. The pressures in opposite ends of the cylinder I59 are thus balanced and the wheel slide stops. tool carriage may now be moved freely by hand or by actuation of the hand traverse mechanism, which, as will later be shown, shuts oil the pipes 315 and 385 from the cylinder I59. In all of the positions of the valve 499, except the stop position, the pipes 451 and 458 are cut ofi from each other by suitable parts of the valve 499. 1

Further depression of the handle 49I bringing the valve 499 into fast position is shown in Figure 35. In this position of the valve 499 the discharge port 423 is closed, but the unrestricted discharge pipe 429 is open through the port 421 and around the neck 4 I 9 of the valve 499 through the discharge pipe 4I4, thus permitting unrestricted discharge of fluid from one or the other side of the power cylinder I59, depending upon the setting of the reversing valve. In this position of the parts, also, the top of the valve 499 is lowered to a point where it is unaffected by the stop 449 so that the traverse may be further extended in an outward direction. The stop 439 is long enough to reverse the traverse at the inner end of its stroke automatically, Y

The stop dog 465'which controls the angular position of the valve M9 and the dog 461 which actuates a work drive valve 951 to be later de- Thescribed are flxed to blocks such as 5 I 9 adjustable within a T slot 5 in a. bracket 5I2 secured to the tool carriage, as best shown in Figure 6, while the dogs 439, 448, and 449 are similarly secured in an under cut groove 5E8 oi the same bracket BIZ. As shown best in Figures 26 and 29, the handle 498 may be rocked angularly by hand in a horizontal plane to turn the valve 499, thus to effect reversal of the direction of traverse at will.

Hand traverse control As before mentioned, the traverse may be controlled by the operator by a manual control of the valve 359, actuation of this valve for such control serving automatically to cut out the automatic traverse conrol. In the inoperative position of the hand control, the parts being in the position of Figures 27 and 31, a hand lever 419 is in vertical position, this lever, as shown in Fig. 31, being pivoted to a link 416, which, in turn, is pivoted to an ear 411 on the cap 418' closing the end of the valve casing 358. The lower end of the hand lever 415 is pivoted at 489 to a rod 48I extending from one end of the valve 359. In Figure 27 a slightly difl'erent mounting of the hand lever 415 is shown in which it is fulcrumed on a fixed pivot 415a and its lower end engages between flanges of a spool 415b carried by the valve rod 48I. At each end of this valve 359 is positioned a spring centering device, this comprising a pair of spring seatmembers 482 and 483. The seat member 482 is perforated for the passage of the rod I and is normally pressed against an end shoulder 484 of the valve by a spring 485 seated in a socket 486 in the cap 418. The spring seat 483 normally engages the opposite end of the valve 359 and is spring pressed by a spring 488 seated in a socket 489 in the end wall member 499 of the valve casing 358. Both of these spring seats 482 and 483 are limited in their inward motion by annular shoulders 499 and 491, respectively, at the ends of the valve casing 358. By pulling the handle 415 outwardly toward the dotted line position shown in Figure 31, the valve 359 is moved to the right against the pressure of the spring 488, this causing the left hand edge of central valve portion 495 to uncover the port 498 to which the pressure pipe 351 leads from the pressure pipe 352. s This allows fluid under pressure to pass directly from the port 496 to the port 319 and to the power cylinder I59 through the pipe I 15, while its shoulder 491 uncovers the port 498 leading to the discharge pipe 499, thus opening up the opposite pipe I 89 from the power cylinder I 59 to discharge, thus causing the cylinder I59 to be moved to the left. At the same time fluid under pressure from the port 496 passing around the valve neck 318 escapes through the passage 599 to the left end of the valve 369, driving it to the right against the pressure of the spring 59I reacting against its right hand end, and shuts off passages leading to the pipes 315 and 385, thus cutting oil the automatic traverse mechanism. On moving the lever 415 inwardly toward the right hand dotted line position of Figure 31, the valve 359 is moved in the reverse direction, opening up the port 499 at the right hand end of the valve port 495 and connecting through the port 389 directly to the pipe I89 leading to the opposite end of the power cylinder I59 so that this power cylinder is driven to the right, the discharge taking place through the pipe I15, passage 319, passage 592 to the discharge pipe 499. Likewise the fluid under pressure may then .passaround the 

